Saturday, December 10, 2011
Here are a few of my favorites from the eclipse this morning. First up, a nice wide view of a partially eclipsed Moon over some Tucson city lights.
Now a zoomed in view.
Back to close up.
And finally, one of the last pics I got before the Moon faded from site due to the brightening sky and the increasingly eclipsed Moon.
Reprinted with permission from the Half-Astrphysicist Blog.
Friday, December 9, 2011
I just posted a blog last night about tomorrow's lunar eclipse. It seems that on facebook and twitter, a lot of people are passing around a story about seeing an impossible site dubbed the selenelion. I am not quite sure this site is so impossible or even so rare and would love comments from other hardcore astronomers/atmospheric physics experts if my thinking is fuzzy or spot on here.
Okay, as I discussed yesterday, a lunar eclipse occurs when the Sun, Moon and Earth are in a perfectly straight line. Therefore, the full, eclipsed Moon should set just as the Sun rises and you don't see them at the same time...assuming Earth has no atmosphere and you have nice flat eastern and western horizons with no buildings/trees/hills etc. But this phenomena happens every month at full Moon! Even if you argue that it's rare because the Moon will be eclipsed, well, every lunar eclipse happens at sunset somewhere in the world so a selenelion happens during every lunar eclipse (of course, the world is 70% ocean so you could argue that many of them occur over water where no one can see them, but it is still not a rare phenomena).
The best I can tell this is "rare" because it is happening over a heavily populated portion of the United States.
But Earth does have an atmosphere. Due to refraction of light by Earth's atmosphere, we see the Sun rise a few minutes earlier than it should and the Moon set a few minutes later than it should. Therefore, you can see both the Sun and the full Moon in the sky at the same time even though it should be impossible if they are 180 degrees apart. This is something I have known for many years (and has been known for a long time) so no new discovery here.So my question is, why is this such a rare event? This happens EVERY MONTH at full Moon. Even if you are at a spot on the world where the sun rises (or sets...this can happen at sunset with the full Moon rising in the east) . Yeah, this is a cool phenomena and I am trying to figure out where I can go to attempt to see it here (lots of mountains in Tucson) because I am fortunate enough to be in the right place at the right time, but it is something that happens during lunar eclipse and even every full Moon!
Reprinted with permission from the Half-Astrophysicist Blog.
1) What was the most memorable Christmas for you?
2) Ever get a Christmas present you didn't want?
3) Do you think politics has changed over the years?
4) What kind of winter sport do you like?
Enjoy your weekend!
Certain lucky people will get treated to a total lunar eclipse on Saturday, December 10th. Unfortunately for many people living in North America, the Moon will set before the total phase of the eclipse begins. For those of us in the west, the totally eclipsed Moon will set in the west as the Sun rises in the east.
Okay, quick review. A total lunar eclipse occurs when the Moon passes through Earth's shadow. That means the Sun, Earth and Moon (in that order) are in a straight line. Lunar eclipses always happen at full Moon, but not every full Moon heralds the arrival of a lunar eclipse (the Moon's orbit is tilted so most months it passes either slightly above or below Earth's shadow). A lunar eclipse is visible to everyone on the side of Earth facing away from the Sun when it occurs (in other words, on Earth's night side).
The penumbral phase (when the Moon enters the very outer part of the shadow) starts at 11:33UT (EST you subtract five hours from UT, CST subtract six, MST subtract 7, and PST subtract 8). The outer part of the shadow is not very dark so you might not notice the Moon get slightly dimmed if you weren't paying attention. The real action stars when the Moon enters the umbra, the dark part of Earth's shadow at 12:45UT. You can watch the Moon get progressively more covered until totality begins at 14:06UT. Totality ends at 14:57UT, the umbral phase ends at 16:17UT and the eclipse is totally over at 17:30UT. Here is a chart from NASA that shows where the eclipse is visible.
In Tucson, sunrise on Saturday is at 7:15am, just nine minutes after totality begins at 7:06am! In reality, the Moon may set a little earlier since there are mountains to the west. I already have my spot to watch and photograph the eclipse picked out. It will be interesting trying to photograph the setting, eclipsed Moon as the sky gets progressively brighter toward sunrise. I suspect there will be lots of great photos of the eclipsed and partially eclipsed Moon setting over scenic areas (Tucson Mountains in my case).
One thing I encourage everyone to do is follow the eclipse on twitter. I did this for last December's total lunar eclipse and it was a lot of fun. There will probably be a twitter hashtag (search for eclipse and you will find it...it might be #eclipse, #lunareclipse or something similar). People will be posting their observations, comments and pictures in real time. You can respond and converse with people about what is happening even if you can't observe it yourself due to your location or local weather conditions. For last Decembers eclipse, there were lots of people observing and conversing, many of whom I knew personally. It was like watching the eclipse with friends even though I was alone with my camera outside my townhome.
Reprinted with permission from the Half-Astrophysicist Blog.
Thursday, December 8, 2011
Wednesday, December 7, 2011
Make your best guess and.... GO TO BED!
Answer revealed tomorrow.
Not a chair wheel, just an overstuffed storage cart's caster. Do we let Drew claim this as a win? He was a bit overconfident with his answer....
Jed did insinuate that I am getting a tad persnickety with the requirements for a win. :o
I know most of those, but not all of them. He's darn good.
Watching this launch is one of my earliest childhood memories. I have vague memories of other Moon missions, but this one is the most clear. It's easy to pin down since it was the only night launch. I was only four years old. I remember watching it and there was a launch delay that I remember taking a long time and that I got to stay up way past my usual bedtime to watch the launch. Boy, was I right! Now I can look stuff up and see that it was a 2 hour and 40 minute delay and Apollo 17 finally launched at 12:33am EST. I was in the central time zone so I saw the launch at 11:33pm, pretty late for a four year old to stay up glued to the television!Gene Cernan and Harrison Schmidt landed on the Moon while Ronald Evans stayed in orbit with the command module. Next year will mark forty years since we last set foot on the Moon. We are long overdue to get back.
Reprinted with permission from the Half-Astrophysicst Blog.
The New York Giants fell, barely, to our glorious Green Bay Packers last Sunday. I mistakenly put the Packers’ record at 12-0 last week. That is their current record. Until this coming Sunday, that is, when the Packers will beat the Oakland Raiders. It starts Dec. 11, 3:15 PM, at Lambeau Field. Destroy the Raiders, please, o mighty Pack. Attack, attack, attack! Slash and cut and hack! Grrr! Oh my, so that’s what testosterone feels like.
As usual, I perused the news for noteworthy topics, but again I found it depressing. In this time of “peace on earth, goodwill to men,” I see little of either. Politics have people at each others throats locally and nationally. So much bitterness. I hope that I offend no one by referring to Christmas. That is the tradition I was brought up in. If yours is Hanukah, or Kwanza, or something else, or nothing, I respect you and your faith. And I truly wish you peace, and I truly wish you goodwill, all year round.
In keeping with the season, here is a tune you’ll recognize, but with a hepcat treatment. The Basily Boys – Gipsy Christmas:
Well, that has me feeling better. I hope that you feel great. Thank you for reading my blog this week. It’s a pleasure to post for your pleasure. I love you all.
Put the X back into your Xmas: firstname.lastname@example.org.
Only 18 more shopping days until Christmas! Oh dear. May the panic of the season be with you - not. Take it easy. Try to savor the holidays. Try to remember that less than perfect is perfectly human. Madame Zoltar watches over you more closely than Santa Claus, and I don’t keep score. Relax. Enjoy. Perceive. Verbigerate.
Pearl Harbor - December 7th, 1941 a date that will live in infamy!
On Sunday, December 7th, 1941 the Japanese launched a surprise attack against the U.S. Forces stationed at Pearl Harbor , Hawaii . By planning his attack on a Sunday, the Japanese commander Admiral Nagumo, hoped to catch the entire fleet in port. As luck would have it, the Aircraft Carriers and one of the Battleships were not in port. (The USS Enterprise was returning from Wake Island , where it had just delivered some aircraft. The USS Lexington was ferrying aircraft to Midway, and the USS Saratoga and USS Colorado were undergoing repairs in the United States .)
In spite of the latest intelligence reports about the missing a aircraft carriers (his most important targets), Admiral Nagumo decided to continue the attack with his force of six carriers and 423 aircraft. At a range of 230 miles north of Oahu , he launched the first wave of a two-wave attack. Beginning at 0600 hours his first wave consisted of 183 fighters and torpedo bombers which struck at the fleet in Pearl Harbor and the airfields in Hickam, Kaneoheand Ewa. The second strike, launched at 0715 hours, consisted of 167 aircraft, which again struck at the same targets.
At 0753 hours the first wave consisting of 40 Nakajima B5N2 "Kate" torpedo bombers, 51 Aichi D3A1 "Val" dive bombers, 50 high altitude bombers and 43 Zeros struck airfields and Pearl Harbor Within the next hour, the second wave arrived and continued the attack.
When it was over, the U.S. losses were:
USA : 218 KIA, 364 WIA.
USN: 2,008 KIA, 710 WIA.
USMC: 109 KIA, 69 WIA.
Civilians: 68 KIA, 35 WIA.
TOTAL: 2,403 KIA, 1,178 WIA.
USS Arizona (BB-39) - total loss when a bomb hit her magazine.
USS Oklahoma (BB-37) - Total loss when she capsized and sunk in the harbor.
USS California (BB-44) - Sunk at her berth. Later raised and repaired.
USS West Virginia (BB-48) - Sunk at her berth. Later raised and repaired.
USS Nevada - (BB-36) Beached to prevent sinking. Later repaired.
USS Pennsylvania (BB-38) - Light damage.
USS Maryland (BB-46) - Light damage.
USS Tennessee (BB-43) Light damage.
USS Utah (AG-16) - (former battleship used as a target) - Sunk.
USS New Orleans(CA-32) - Light Damage..
USS San Francisco(CA38) - Light Damage.
USS Detroit(CL-8) - Light Damage.
USS Raleigh (CL-7) - Heavily damaged but repaired.
USS Helena(CL-50) - Light Damage.
USS Honolulu(CL-48) - Light Damage..
USS Downes (DD-375) - Destroyed. Parts salvaged.
USS Cassin - (DD-37 2) Destroyed. Parts salvaged.
USS Shaw (DD-373) - Very heavy damage.
USS Helm (DD-388) - Light Damage.
USS Ogala (CM-4) - Sunk but later raised and repaired.
USS Curtiss (AV-4) - Severely damaged but later repaired.
USS Vestal (AR-4) - Severely damaged but later repaired.
USS Sotoyomo (YT-9) - Sunk but later raised and repaired.
188 Aircraft destroyed (92 USN and 92 U.S. Army Air Corps
Tuesday, December 6, 2011
So, what was really found. First, a review of how Kepler works. Kepler is basically staring at one area of the sky and monitoring the brightnesses of about 150,000 stars. If a planet is orbiting the star, there is a chance it will line up and pass directly in front of the star. Kepler will see the star get a bit dimmer for a little while (usually on the order of hours) as the planet transits (passes in front of) the star. When we say a bit dimmer, it means only one part in 10,000 or so, not very easy to detect which is one of the reasons this is a space based mission. From this information, you can tell if there is a planet there. Based on how long the transit takes, you can get an estimate of the radius of the planet (but not its mass...that requires follow up spectroscopy where you measure the stars wobble as the planet orbits it).
In order to qualify as a planet candidate, you need to see the star dim three times. First time, you know something happened but it might not have been a planet. Second time, pretty much same thing. Third time, you can say you have a planet candidate if the time between the first and second transit is the same as the time between the second and third transit. This pattern indicates the star is dimming with a regular period just like you would expect if a planet was orbiting it.
Kepler got lucky with this planet. Its first transit was detected only three days after Kepler started taking science data. The next one, 290 days later and the third, another 290 days later. The planet, dubbed Kepler-22b was found about as quick as it could be since its first transit was detected almost immediately (imagine if you missed it by one day...then you would have had to wait another 290 days! It's almost certain there are planets that were just missed).
So Kepler-22b orbits the star every 290 days. It's a little closer to its star than Earth is to the Sun, but that's okay since the star is a little smaller and not quite as bright. It sits in what is commonly called the habitable zone: a place where a planet similar to Earth could have liquid water on its surface.
There's the catch: Similar to Earth. Kepler-22b is about 2.4 times the diameter of Earth, so quite a bit bigger (that's almost 14 times the volume!) It's not clear if the planet is predominantly rocky like Earth. The planet could have a very thick or non-existent atmosphere. It could rotate way too fast or way too slow (resulting in a hot side and a frozen side). It could have its axis of rotation tipped on its side like Uranus. There are lots of ways it could be far from an Earth-like planet!
Of course this just gets astronomers excited to study it further. We can determine its mass by measuring the Doppler shift it imparts on the star as the planet orbits and hence determine if it is a rocky planet like Earth. Advanced spectroscopic techniques can be used to examine the planets atmosphere. These further studies (which you can bet are already being planned) will start to unravel some of the mysteries of Kepler-22b. I think Kepler Program Scientist Douglas Hudgins says it well, "This is a major milestone on the road to finding Earth's twin."
Lost in this hoopla is that they also announced over 1,000 new planet candidates (and that it looks like about 99% of their candidates are turning out to be planets, so they have a pretty good batting average).
The good news is that even if Kepler-22b turns out to be not quite so habitable, there are a lot more in the pipeline awaiting confirmation (looks like around 140 more, give or take a few based on where you draw the line for the habitable zone). These all need to be followed up and maybe in the next few years, we will nail down that true Earth-like planet.
Reprinted with permission from the Half-Astrophysicist Blog.
Monday, December 5, 2011
They had to combine data from several telescopes including the 8 meter Gemini Telescope in Hawaii, the 10 meter Keck Telescope in Hawaii and the Mitchell Spectrograph on the 2.7 meter telescope at McDonald Observatory in Texas. By measuring how fast stars and gas are orbiting the black hole, you can calculate the mass of the black hole.
In spite of the amazingly large mass of the black holes, they are not large on the cosmic scale. The event horizons of these beasts (the point of no return where not even light can escape) is about 200 times the distance from the Earth to the Sun (commonly called an astronomical unit, or a.u.). And we don't need to worry about these guys...they are both over 300 million light years away (and we have a pretty good size black hole much closer to us at the center of our galaxy which we are happily orbiting right now and don't have to worry about it either!)
These black holes probably formed by the mergers of black holes in smaller galaxies and astronomers are very interested in figuring out the details of how these super massive black holes form. These black holes may be the same ones that powered quasars in the early universe but have run out of the supply of gas and dust that powered quasars billions of years ago.
Now when I first read this story it jogged a circuit in my brain that recalled a story from a couple of years ago that astronomers had found evidence that there is a limit to the size of the largest black holes. Sure enough, I quickly found that article again. Priyamvada Natarajan, an associate professor of astronomy and physics at Yale University and a fellow at the Radcliffe Institute for Advanced Study, found an upper limit for the mass of black holes at (drum roll, please!) 10 billion solar masses!
Now I am sure Gebhardt and Murphy are already hard at work looking at more galaxies and trying to find even more massive black holes and they would love to break the 10 billion solar mass rule and make astronomers rethink their ideas on black hole formation and evolution!
Reprinted with permission from the Half-Astrophysicist Blog.
Sunday, December 4, 2011
That's all. It's not much, but I'll take any good news that I can get.
Some facts I found while perusing the information highway:
-Standard servings... 1 beer = 5 ounces of wine = 1 shot of alcohol.
-Champagne has more alcohol content than standard wine.
-The body takes about 1/2 hour to feel the effects of alcohol.
-A standard 750 ml bottle of wine contains 5 servings.
-A fifth contains 17 standard servings (1.5 oz)
-Coffee is not successful at sobering up a drunk person.
-Time is the only way to remove alcohol from your system.
-A "beer belly" is caused by eating too much food, not alcohol.
-Morphine injections were used by physicians to treat alcoholism in the early 20th century.
This is not exactly the quiz I had in mind when I went searching, but it was interesting, none-the-less. I scored 8 out of 10. I'm blaming my misses to the fact that I'm a lightweight... and why in the world did they feel they had the right to bring my cerebral cortex into this picture, hmmm? ;>